package com.yuanxiao.coder;

import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.ByteToMessageDecoder;

import java.util.List;

public class RpcDecoder  extends ByteToMessageDecoder {
    private Class<?> clazz;

    private Serializer serializer;


    public RpcDecoder(Class<?> clazz, Serializer serializer) {

        this.clazz = clazz;

        this.serializer = serializer;

    }

    @Override
    protected void decode(ChannelHandlerContext channelHandlerContext, ByteBuf byteBuf, List<Object> list) throws Exception {
        if(byteBuf.readableBytes()<4){
            return;
        }
        byteBuf.markReaderIndex();
        int dataLength=byteBuf.readInt();
        if(byteBuf.readableBytes()<dataLength){
            byteBuf.resetReaderIndex();
            return;
        }
        byte[] data=new byte[dataLength];
        byteBuf.readBytes(data);
        list.add(serializer.deserialize(clazz,data));
    }

}

